Tire pressures in snow?
#31
JK Newbie
Join Date: Oct 2008
Location: Orchard Park, NY
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I think that you should probablly take the advice of the numerios people on the forum saying that it is better to air down and have proof in pictures that airing down actually helped them out instead of the one guy saying to add a few pounds.
#32
JK Super Freak
Now personally I don't have the answer, but I'm gonna be testing both here tomorrow before I hit the trails full of snow on Saturday...I'll post my unbiased opinions tomorrow.
I do find this most interesting though and am VERY curious to get to the bottom of this.
Further more..by spending a few spare sleepless hours last night I cruised the net up and down and it would appear that there remains TWO definate schools of thought on this very subject, both sides with great arguments and evidence, I have yet to find a definative answer...but you can do what you want
#34
Been wheelin' in my own rigs for 20 + years now, (not Army issue). Snow that will touch your axle or undercarriage, AIR DOWN. Less snow than that, turn off ESP and do donuts in your front yard.... Don't believe me? Stay full pressure in deep snow and freeze your but off overnight... Why do you think cold weather HMMWV and such have a central tire inflation system....it is not for run flat....
#35
JK Freak
You gents may have seen this video before...
I very much doubt that the kid aired-down his TJ prior to driving that morning.
I'd say 16+ inches of snow.
http://www.youtube.com/watch?v=RxQhuwMNOVs
Oh yeah, I almost forgot. Hardness of Goodyear SR-As at 17 degrees F: Shore A 65. BFG MT KM2s: Shore A 85. Measurements taken on tread, three locations.
My regards,
Widewing
I very much doubt that the kid aired-down his TJ prior to driving that morning.
I'd say 16+ inches of snow.
http://www.youtube.com/watch?v=RxQhuwMNOVs
Oh yeah, I almost forgot. Hardness of Goodyear SR-As at 17 degrees F: Shore A 65. BFG MT KM2s: Shore A 85. Measurements taken on tread, three locations.
My regards,
Widewing
#36
I figured that I would contact B.F. Goodrich and request their opinion on airing-down for trail riding in snow.
From B.F. Goodrich via e-mail received today:
"Thank you for your email.
BF Goodrich does not recommend reducing the inflation pressure on your tires
to drive trails in the snow. You need to still have enough air to handle
the load requirements of the vehicle and that is the air pressures stated on
the placard between your door jams and put there by the vehicle
manufacturer. Driving on any surface or terrain with extreme low linflation pressure
will damage the tires and the possibility of damaging the vehicle and physical injury
be ignored."
My regards,
Widewing
From B.F. Goodrich via e-mail received today:
"Thank you for your email.
BF Goodrich does not recommend reducing the inflation pressure on your tires
to drive trails in the snow. You need to still have enough air to handle
the load requirements of the vehicle and that is the air pressures stated on
the placard between your door jams and put there by the vehicle
manufacturer. Driving on any surface or terrain with extreme low linflation pressure
will damage the tires and the possibility of damaging the vehicle and physical injury
be ignored."
My regards,
Widewing
Air pressure (footprint). vehicle weight, momentum and driver right foot weight all add to the moving through snow factor....
#37
JK Enthusiast
Join Date: Jan 2009
Location: York, PA
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I hear you there - the idea is to increase your contact area psi, in order to hit solid traction, aye? Same idea behind pizza cutters working better in deep snow?
I've always debated this myself. Do you air down knowing that when you do hit the rocks you'll want that surface area versus the higher psi and overall trail traction?
Can't wait to continue the debate this weekend
I've always debated this myself. Do you air down knowing that when you do hit the rocks you'll want that surface area versus the higher psi and overall trail traction?
Can't wait to continue the debate this weekend
#38
JK Super Freak
Join Date: Jun 2008
Location: Calgary, Alberta, Canada
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Been wheelin' in my own rigs for 20 + years now, (not Army issue). Snow that will touch your axle or undercarriage, AIR DOWN. Less snow than that, turn off ESP and do donuts in your front yard.... Don't believe me? Stay full pressure in deep snow and freeze your but off overnight... Why do you think cold weather HMMWV and such have a central tire inflation system....it is not for run flat....
+1
Gee...another guy that lives in a place with mountains (and lots of snow) who's figured it out. 12 or 16 or 18 inches of snow will be solved by a good tire and 4X4. Beyond that (once you're dragging your pumpkins) you had better start looking for flotation.
There's a reason that snowmobiles designed for mountain use (deep snow vs. groomed trails) have longer tracks.
Pizza cutters work great...up to a point. If your diffs and the belly of your vehicle will end up high-centering you, then you don't want pizza cutters. Choose your technique based upon the conditions.
#39
If it gets up to 20 deg F tomorrow I will be wheeling in deep snow tomorrow with some friends.
For off road I will be dropping to 10 PSI cause I dont like wheel hop and I dont want to get stuck if I can help it.
Deep fresh snow on a road is totally different than the off road stuff that has been sitting for awhile before you go to brake a trail. I dont know why but this is something that I have learned.
Off road if you sink in you are stuck for awhile.
For off road I will be dropping to 10 PSI cause I dont like wheel hop and I dont want to get stuck if I can help it.
Deep fresh snow on a road is totally different than the off road stuff that has been sitting for awhile before you go to brake a trail. I dont know why but this is something that I have learned.
Off road if you sink in you are stuck for awhile.
#40
JK Freak
I've seen Leopard I battle tanks get stuck in extremely dense snow. This type of snow results from repeated heavy snow falls that compacts the previous snow into increasingly dense layers. The bottom layers have the consistency of nearly cured concrete. The tank's flat bottom eventually came to rest on super-dense layers with the tracks whirring around, unable to get a bite. It took two recovery vehicles, chained together to winch the Leopard out. Snow depth was almost 3 meters.
My regards,
Widewing